The Bear was an adventure and unlike anything I've ever done outside of the USA, (I've also done Zion 100 and am off to do the inaugural Tahoe 200 in a few weeks)
What really struck me - apart from the incredible scenery was the ultra community in the US, it's a lot more established, but still really welcoming. I met people at The Bear and Zion that I still keep in touch with - the yanks are incredibly interested in the European scene, especially fell running for some reason!
If you have the time and money, then get out and do some racing in the USA - the ultra / trail running scene is massive and there are races every weekend to choose from.
I did the NDW100 in 2012 - it is a great event and I have no doubt Centurion will put on a fantastic day as ever
Tips... take the first half easy, there's some big hills - Box Hill and Reigate hill especially. Be prepared for some more nasty hills and steps after the Detling aid station and it's more than 100 miles, maybe only by 3 or 4 miles, but that can take you an hour after already doing 100 miles!
The Centurion site has great pacing for sub 24 - if you can get to halfway in 10 hours you're game-on for a sub-24 finish... In 2012, I got to halfway in 10:30 and finished in 23:46 and nobody passed me after halfway.
I did Palma as my first marathon in 2010 and again in 2012. It's quite a big marathon, the first half is nice and scenic, around the marina and through the old town. The second half can be a bit of a lonely out-and-back up the coast to Arenal...
In 2012 there were lots of problems with buses to the start from Arenal where I was staying, there weren't enough buses, taxis were non-existent and they shut the roads while we were still waiting. Eventually we got there with minutes to spare so it was a mad dash to check bags and get to the start line - but not a great start.
Otherwise, yep - it's a nice enough road race. Pretty flat, the first half is great fun and well supported on wide roads initially to allow the pack to spread out. It can be warm, but also windy on final 10km back into Palma.
Lots and lots of Germans do it, (Palma has big Germanic connections) - beer at the finish - but alas, it's non-alcoholic Erdinger! Quite a few brits too - and Palma is a nice enough place to spend a day-or-two after, assuming you don't want to go Jeremy Kyle baiting in Magaluf